OBJECTIVE: The aim of this study was to prospectively assess the development of 24 urinary, gastrointestinal and sexual symptoms in patients with prostate cancer (PCa) during and after image-guided volumetric modulated arc therapy (IG-VMAT). MATERIAL AND METHODS: A total of 87 patients with PCa participated in this study. The patients were asked to complete a modified version of the Prostate Cancer Symptom Scale (PCSS) questionnaire before radiotherapy (RT) (baseline), at the start of RT, at the end of RT and 1 year after RT. Changes in symptoms at the start of RT, at the end of RT and 1 year after RT compared to baseline were analysed by a mixed model analysis of repeated measurements with the following covariates: age, comorbidity, smoking and androgen deprivation therapy (ADT). RESULTS: All urinary problems except for haematuria increased significantly at the end of RT compared to baseline. One year after RT, there was no longer any difference compared to baseline for any of the urinary symptoms. All gastrointestinal symptoms except for nausea increased significantly at the end of RT. One year after RT, patients also reported slightly higher degrees of stool frequency, bowel leakage, planning of toilet visits, flatulence, mucus, gastrointestinal bleeding and impact of gastrointestinal bother on daily activities compared to baseline. All sexual symptoms increased significantly at all times compared to baseline. The use of ADT was associated with worse sexual symptoms. CONCLUSIONS: IG-VMAT is a safe treatment for PCa, with few and mild changes in urinary and gastrointestinal symptoms 1 year after RT compared to baseline. Sexual symptoms deteriorated both during and after RT. The use of ADT was associated with worse sexual symptoms.